Thermomagnetically written domains in TbFeCo thin films

Characteristic features of thermomagnetically written domains in amorphous Tb_x(Fe₉₀Co₁₀)_100-x thin films having different magnetic properties are reported. In particular, the writing process in materials with low Tb content (x⩽21), which is dominated by the demagnetizing field, is compared to the bias-field-dominated process in Tb-rich samples (22⩽x⩽25). Domain-wall movement over lateral dimensions of the bit size is found for Tb-poor materials, while for x⩽22 the domain boundaries are primarily determined by the area heated up to the Curie temperature. The importance of mechanical stress in domain formation and irreversible changes of the storage medium due to overheating in the writing process are reported